The Bretton Woods Conference helped develop the World Bank and the International Monetary Fund (IMF). Why was America concerned with making sure that European countries received money?

To make European countries buoyant enough to be an important market for American exports.

Explanation:

The Bretton Woods Conference, which was carried out in 1944, was made to promote international trade while maintaining the independent policy goals of separate nations.

However, during the early years around 1946 to 1948 of its implementation, the European countries were running balance-of-payments shortages, leading to an increase in immediate need of their dollar and gold reserves.

Because of this situation, the United States felt that European countries wouldn't buy their goods as exports if they don't have money.

Hence the reason America was concerned with making sure that European countries received money is "to make European countries buoyant enough to be an essential market for American exports."